<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			@media only screen and (max-width: 800px) {
				body{
					background: red;
				}
				h1{
					color: white;
				}
			}
			@media only screen and (min-width:801px ) {
				body{
					background: blue;
				}
				h1{
					color: yellow;
				}
			}
		</style>
	</head>
	<body>
		<h1>后盾人     人人做后盾</h1>
	</body>
</html>
